Words change meaning all the time — and over time. Language historian Anne Curzan takes a closer look at this phenomenon, and shares some words that used to mean something totally different.

Words change meaning over time in ways that might surprise you. We sometimes notice words changing meaning under our noses (e.g., unique coming to mean “very unusual” rather than “one of a kind”) — and it can be disconcerting. How in the world are we all going to communicate effectively if we allow words to shift in meaning like that?

The good news: History tells us that we’ll be fine. Words have been changing meaning — sometimes radically — as long as there have been words and speakers to speak them. Here is just a small sampling of words you may not have realized didn’t always mean what they mean today.

Nice: This word used to mean “silly, foolish, simple.” Far from the compliment it is today!

Silly: Meanwhile, silly went in the opposite direction: in its earliest uses, it referred to things worthy or blessed; from there it came to refer to the weak and vulnerable, and more recently to those who are foolish.

Awful: Awful things used to be “worthy of awe” for a variety of reasons, which is how we get expressions like “the awful majesty of God.”

Fizzle: The verb fizzle once referred to the act of producing quiet flatulence (think “SBD”); American college slang flipped the word’s meaning to refer to failing at things.

Wench: A shortened form of the Old English word wenchel (which referred to children of either sex), the word wench used to mean “female child” before it came to be used to refer to female servants — and more pejoratively to wanton women.

Fathom: It can be hard to fathom how this verb moved from meaning “to encircle with one’s arms” to meaning “to understand after much thought.” Here’s the scoop: One’s outstretched arms can be used as a measurement (a fathom), and once you have fathoms, you can use a fathom line to measure the depth of water. Think metaphorically and fathoming becomes about getting to the bottom of things.

Clue: Centuries ago, a clue (or clew) was a ball of yarn. Think about threading your way through a maze and you’ll see how we got from yarn to key bits of evidence that help us solve things.

Myriad: If you had a myriad of things 600 years ago, it meant that you specifically had 10,000 of them — not just a lot.

Naughty: Long ago, if you were naughty, you had naught or nothing. Then it came to mean evil or immoral, and now you are just badly behaved.

Eerie: Before the word eerie described things that inspire fear, it used to describe people feeling fear — as in one could feel faint and eerie.

Spinster: As it sounds, spinsters used to be women who spun. It referred to a legal occupation before it came to mean “unmarried woman” — and often not in the most positive ways, as opposed to a bachelor …

Bachelor: A bachelor was a young knight before the word came to refer to someone who had achieved the lowest rank at a university — and it lives on in that meaning in today’s B.A. and B.S degrees. It’s been used for unmarried men since Chaucer’s day.

Flirt: Some 500 years ago, flirting was flicking something away or flicking open a fan or otherwise making a brisk or jerky motion. Now it involves playing with people’s emotions (sometimes it may feel like your heart is getting jerked around in the process).

Guy: This word is an eponym. It comes from the name of Guy Fawkes, who was part of a failed attempt to blow up Parliament in 1605. Folks used to burn his effigy, a “Guy Fawkes” or a “guy,” and from there it came to refer to a frightful figure. In the U.S., it has come to refer to men in general.

Hussy: Believe it or not, hussy comes from the word housewife (with several sound changes, clearly) and used to refer to the mistress of a household, not the disreputable woman it refers to today.

Egregious: It used to be possible for it to be a good thing to be egregious: it meant you were distinguished or eminent. But in the end, the negative meaning of the word won out, and now it means that someone or something is conspicuously bad — not conspicuously good.

Quell: Quelling something or someone used to mean killing it, not just subduing it.

Divest: 300 years ago, divesting could involve undressing as well as depriving others of their rights or possessions. It has only recently come to refer to selling off investments.

Senile: Senile used to refer simply to anything related to old age, so you could have senile maturity. Now it refers specifically to those suffering from senile dementia.

Meat: Have you ever wondered about the expression “meat and drink”? It comes from an older meaning of the word meat that refers to food in general — solid food of a variety of kinds (not just animal flesh), as opposed to drink.

We’re human. We love to play with words in creative ways. And in the process, we change the language. In retrospect, we often think the changes words undergo are fascinating. May we transfer some of that fascination and wonder — some of the awe that used to make the words awful and awesome synonymous — to the changes we’re witnessing today.